Movable bolster lowering arrangement



Patented Jan. 21, 1969 6 Claims ABSTRACT OF THE DISCLOSURE Improvedcarrier lowering mechanism for a press having a bed, a frame, a ramcarried by the frame and movable vertically toward and away from thebed, tracks extending in a first direction from a position exterior ofthe press into and across the bed, and a carrier having wheelsengageable with the tracks for guiding the carrier therealong from afirst position exteriorly of the press to a second position in the pressand beneath the ram. The mechanism includes first track forming membershaving upwardly facing surfaces downwardly inclined in a directionperpendicular to the first direction. The track forming members arepositioned in the bed at locations corresponding to the locations of thewheels when the carrier is in the second position to thus support thewheels on the upwardly facing surfaces. Selectively operable power meansare provided for moving the track forming members horizontally in thesecond direction away from the wheels to permit the wheels and thecarrier to be lowered.

The present invention is directed to the press art and more particularlyto an improved movable bolster lowering arrangement.

The invention is especially suited for use in changing dies in metalworking presses and it will be described with particular referencethereto; however, it is appreciated the invention is capable of broaderapplication and could be used wherever it is desired to leave a materialor die carrier in position in a press during press operation.

It is common practice in the press art to provide metal working presseswith movable bolster arrangements to facilitate changing die sets. Oneof the most commonly used arrangements comprised a wheeled bolster ordie carrier which was guided on tracks that extended from a positionoutside the press into and across the press bed. When it was desired tomove a die set into the press, the lower die of the set was bolted orclamped to the carrier and the upper die positioned in matedrelationship on the lower die. The carrier was then rolled into thepress and the press ram actuated downwardly into engagement with the topsurface of the upper die connected thereto.

In order to provide a firm foundation for the lower die and carrier, andalso, to relieve the impact load from the carrier wheels during pressoperation, the tracks in the press bed were arranged to be lowered. Thisallowed the bottom of the carrier to be brought into engagement with thepress bed. Further, mechanism was provided to clamp the lowered carrierto the bed to avoid shifting during press operation.

Generally, the above-mentioned track lowering and carrier clampingmechanism took the form of vertically arranged hydraulic or pneumaticcylinders mounted in the press bed and connected to the tracks andclamps. Because of the substantial weight of the dies and the diecarrier, the cylinders were quite large. This necessitated the provisionof large openings in the press bed and eliminated space otherwise neededfor knock-out cylinders, etc. Additionally, because the cylinders werepositioned a substantial distance down in the bed, problems wereencountered in performing necessary maintenance and repair.

The present invention overcomes the above problems and provides abolster lowering and clamping mechanism which is arranged for mountingadjacent the top surface of the press bed and eliminates the need forvertically positioned actuating mechanism extending down into the bed.Additionally, the invention permits lowering, locating and clamping ofthe bolster to be accomplished simultaneously with a single mechanism.

In accordance with the present invention an improved carrier loweringmechanism is provided for a press having a bed, a frame, a ram carriedby the frame and movable vertically toward and away from the bed, tracksextending in a first direction from a position exterior of the pressinto and across the bed, and a carrier having wheels engageable with thetracks for guiding the carrier therealong from a first positionexteriorly of the press to a second position in the press and beneaththe ram. The improved means comprise means operable when the carrier isin the second position for lowering the carrier against the bed andrelieving the weight of the carrier from the wheels. The means includefirst track forming members having upwardly facing surfaces downwardlyinclined in a direction perpendicular to the first direction. The trackforming members are positioned in the bed at locations corresponding tothe locations of the wheels when the carrier is in the second positionto thus support the wheels on the upwardly facing surfaces. Selectivelyoperable power means are provided for moving the track forming membershorizontally in the second direction away from the wheels to permit thewheels and the carrier to be lowered.

Because the movement of the track forming members is always horizontal,the actuating or power means can readily be positioned in a horizontalposition adjacent the top surface of the press bed. This eliminates theproblems previously encountered with vertically mounted actuating means.Further, because the movement of the track forming members ishorizontal, it is a simple matter to include both locating and clampingelements on the track forming members.

Accordingly, it is a primary object of the present invention to providea bolster or carrier lowering mechanism wherein all movements of theelements comprising the mechanism are in a horizontal direction.

Another object of the present invention is to provide a bolster loweringmechanism wherein the lowering locating, and clamping of the bolster areaccomplished by a single mechanism.

A further object is the provision of a bolster lowering mechanismwherein all parts of the mechanism are located adjacent the top surfaceof the press bed.

These and other objects and advantages will become apparent from thefollowing description used to illustrate preferred embodiments of theinvention when read in connection with the accompanying drawingswherein:

FIGURE 1 is an elevational view, somewhat diagrammatic, of a presshaving a movable bolster arrangement constructed in accordance with thepresent invention;

FIGURES 2 and 2A are cross-sectional views taken on 3 line 22 of FIGURE1 and showing the bolster lowering mechanism in its bolster raised andbolster lowered positions respectively;

FIGURE 3 is a view taken on line 33 of FIGURE 2A;

FIGURES 4 and 4A are cross-sectional views similar to FIGURES 2 and 2Ashowing a modified form of bolster lowering mechanism constructed inaccordance with the present invention;

FIGURE 5 is a cross-sectional view showing the manner in which a clampcan be included on the modification of FIGURE 4; and,

FIGURE 6 is a view taken on line 6-6 of FIGURE 5.

Referring now to the drawings wherein the showings are for the purposeof illustrating a preferred embodiment of the invention only and not forthe purpose of limiting same, FIGURE 1 shows the overall arrangement ofa metal working press A provided with a movable bolster assembly Bconstructed in accordance with a preferred embodiment of the presentinvention.

The precise arrangement and construction of press A is not important tothe present invention. However, as shown in FIGURE 1, the presscomprises a bed 10 provided with four vertically extending uprights 12which carry an upper ram 14 mounted for vertical reciprocation towardand away from the bed 10. Although only two uprights 12 are shown, itwill be understood that a second pair of uprights are positioneddirectly behind the pair shown and spaced a distance therefromsufiicient to allow bolster assembly B to be rolled therebetween intoposition in the press.

A pair of transversely spaced guideways in the form of tracks 16 extendfrom a position exteriorly of the press into and across the press bed.Tracks 16 provide means for guiding the movement of bolster assembly Bfrom an exterior position shown dotted in FIGURE 1, to a locatedposition within the press and beneath the press ram as shown in solidlines in FIGURE 1.

Bolster assembly B includes a main frame 20 provided with support meansshown in the form of Wheels 22 rotatably mounted on axles 22a andadapted to ride on tracks 16. This permits the carrier to be easilyrolled into and out of the press so that a die set 23 can be brought toworking position within the press.

As shown in FIGURE 1, the die set would normally include an upper diehalf 25 and a lower die half 26. The dies are positioned on the carrierwhile it is outside the press as shown in dotted lines in FIGURE 1. Thelower die half 26 is clamped or bolted to the top of the frame 20 andthe upper die half 25 positioned in mated relation thereon. The carrieris then rolled along tracks 16 to the located position within the press.At this time, means function to lower the bottom of the carrier intoengagement with the top surface of the bed to thereby relieve the loadfrom the wheels and firmly position the carrier. Subsequent to thelowering of the carrier the ram 14 is moved downwardly into engagementwith the top surface of upper die half 25 and clamped or bolted thereto.The press is then ready for operation.

Of particular importance to the present invention are the means providedto perform the function of lowering the carrier into engagement with thebed of the press. As shown in FIGURES 2, 2A and 3, tracks 16 are formedwith a generally V-shaped groove so as to provide a pair of upwardlyfacing downwardly inclined carrier support surfaces 30. The outerperiphery of wheels 22 are provided with a generally V-shapedconfiguration so as to provide a pair of surfaces 32 adapted to ride onthe track surfaces 30. Preferably, a narrow center band of the outerperiphery of wheels 22 is flat as shown at 31. This permits the carrierto ride on a simple flat surface or tracks in the form of a channelhaving a flat bottom surface, without subjecting the surface to highpoint loads as would result from a pointed periphery.

As shown in FIGURE I, mounted in the press bed at locationscorresponding to the locations of wheels 22 when the carrier is in thelocated position under the ram, are lowering assemblies 34. Each ofthese lowering assemblies 34 comprise a pair of track forming members 36which are mounted in openings 38 formed in the top surface of the pressbed 10. Members 36 are arranged so that when they are in the positionshown in FIGURE 2 their top surface defines a continuation of surfaces30 of tracks 16 and thus support the carrier above the press bed.However, when members 36 are reciprocated apart to the position shown inFIGURE 2A, their top surfaces are moved horizontally away from surfaces32 of wheels 22 and the carrier permitted to lower until its bottom 39engages the top surface of bed 10. Conversely, when the members 36 arereciprocated from the position of FIGURE 2A, inwardly to the positionshown in FIG- URE 2, the top surfaces of the members 36 engage theinclined surfaces 32 of the periphery of wheel 22 and through a wedgingaction lift the wheel and carrier to the position at which it can befreely rolled along tracks 16.

Although it is apparent that the top surfaces of members 36 could beformed as a simple machined surface, the surfaces are preferably definedby horizontally positioned rollers 40 mounted with their axes ofrotation extending parallel to the direction of the track. This reducesthe frictional forces acting between the wheels and the track formingmembers and reduces the force required to reciprocate the members.

A variety of types of power means or actuators, such as motor drivenscrews or air cylinders, could be utilized for selectively reciprocatingmembers 36 to raise and lower the bolster assembly B. However, accordingto the preferred embodiment the means utilized comprise hydrauliccylinders 42 fixedly mounted in the bottom of each opening 38. Each ofthe cylinders has a pair of pistons 44 each connected to a piston rod 46which extends through the end walls of cylinder 42 into engagement withthe bottom portion of one of the track forming members 36. Hydrauliclines (not shown) are provided to supply hydraulic fluid under pressurebetween pistons 44 to move them apart and thus, move the track formingmembers 36 to the carrier lowered position shown in FIGURE 2A.Additionally, hydraulic lines are connected to the space between thepistons 44 and the end walls of the cylinder so that hydraulic fluidunder pressure can be supplied to drive the piston to the position shownin FIGURE 2 to move the track forming members 36 to the carrier raisedposition. Various automatic control means could obviously be provided tocontrol the supply of hydraulic fluid to the cylinders.

With the lowering mechanism constructed in the manner described, theproblems of vertically positioned actuating mechanisms are eliminated.Further, the present arrangement permits locating and clamping of thecarrier to be accomplished by the same mechanism. As shown in FIGURES 13the left track forming member 36 is provided with a pair of upwardlyextending portions 50 having a laterally extending wedge clamp member 52formed thereon. A corresponding wedge clamp member 54 is formed on theundersurface of carrier frame 20. Additionally, laterally extendingclamp members 56 are formed on the bottom of member 36 and arranged tobe received in an opening 58 formed in the left wall of bed opening 38.As is apparent from FIG- URES 2 and 2A, the final movement of left trackforming member 36 to the left causes clamp members 52 and 56 to engagecarrier clamp member 54 and opening 58 respectively. This securelyclamps the carrier to the bed.

The invention also permits final locating of the carrier to beaccomplished by the same lowering mechanism. As shown, small rollers 60having their axes extending vertically are mounted on the top surfacesof members 50. Carrier frame is provided with vertically extendingsurfaces 62 arranged as shown in FIGURE 3. Consequently, if the carrieris not precisely located prior to lowering, initial movement of thetrack forming member to the left causes one of the rollers 60 to engagethe corresponding surface 62 and move the carrier to the proper positionlongitudinally of the track. In this manner, locating is accomplishedsimultaneously with lowering.

A second modification of the present invention is shown in FIGURES 4 and4A. According to this modification, the tracks 16 are formed so as toprovide a single downwardly inclined upper carrier support surface andan upwardly extending flange 29. The wheels 22 are in the form oftruncated cones to provide an outer periphery having a correspondinginclined surface 32. Additionally, a narrow cylindrical band 31' isprovided to permit the wheels to be used on a flat surface if desired.

Each of the lowering assemblies 34' are located in the press bed in themanner described above with reference to the FIGURE 2 embodiment andassemblies 34' include a track forming member 36' having an uppersurface which forms a continuation of track surface 30. Preferably theupper surface is defined by a pair of rollers arranged in the mannerdescribed with reference to the FIGURE 2 embodiment.

As is apparent from FIGURES 4 and 4A, movement of track forming member36' to the left permits the wheel 22' and the carrier to be lowered intoengagement with the top of press bed 10. Conversely, movement to theright lifts the carrier.

A variety of power means could be utilized for moving track formingmember 34; however, the means preferably comprise a double actinghydraulic cylinder 70 having its piston rod 72 connected to the lowerportion of track forming member 36' in the same manner as describedabove with reference to the FIGURE 2 modification.

FIGURES 5, 5A and 6 show an arrangement which provides forsimultaneously lowering and clamping of the carrier. Although thismodification has been shown with particular reference to a loweringassembly of the type shown in FIGURE 4A, as will become apparent, thesame clamping arrangement can be utilized with either the FIGURE 2 orFIGURE 4 embodiments. The modification shown in FIGURE 5 is generallysimilar in all respect to the FIGURE 4 embodiment. However, to providefor clamping of the carrier after it has been brought into engagementwith the press bed, a clamping member 74 extends vertically upward fromthe top of track forming member 36'. Member 74 is provided with alaterally extending wedge shaped portion 76 which provides a downwardlyfacing inclined clamp surface 78. A second clamp member 80 is connectedto the frame 20 of the carrier. Member 80 is provided with an upwardlyfacing inclined clamp surface 82 which is arranged to be engaged bysurface 78 of clamp member 74. Additionally, in order to permit thetrack forming member 36' to resist vertically directed forces, themember is retained in opening 38' by a pair of bars or retaining guides84 connected to opposite walls of opening 38 by screws 86. The portionof member 36 below guides 84 extends under each of the guides and isthereby retained in the opening. As shown in FIGURE 5A, as track formingmember 36' is moved to the left to lower the carrier, the surface 78comes into engagement with surface 82 and firmly clamps the carrier tothe bed. This arrangement eliminates the necessity of providing separateclamp actuating means in the press bed.

Although certain specific embodiments have been described in detail, itis apparent that many modifications and alterations of the describedembodiments can be made without departing from the invention as setforth in the appended claims. For example, either of the embodiments ofFIGURES 4 or 5 could be provided with locating means as shown in FIGURE2. Likewise, the FIGURE 2 embodiment could be utilized without theclamping or (locating means. Additionally, in any one press installationany number of the lowering assemblies could be provided with locatingand clamping means. These and other modifications of the preferredembodiments will occur to others upon a reading and understanding of thespecification and it is our intention to include all such modificationsand alterations 'as part of our invention insofar as they come withinthe scope of the appended claims.

Having thus described our invention, we claim:

1. In a press having a bed, a ram movable toward and away from said bed,guideway forming means having an upwardly facing support surfaceextending in a first horizontal direction from a position exterior ofsaid press into and across said bed, a carrier having a frame includingsupport members extending into engagement with said upwardly facingsupport surface of guideway forming means for supporting said framethereabove for guided movement therealong from a first position exteriorof said press to a second position within said press and beneath saidram, the improvement comprising: lowering means for lowering the frameof said carrier into engagement with said bed and relieving the weightof said carrierfrom said support members when said carrier is in saidsecond position; said lowering means including: at least the portions ofsaid upwardly facing support surface of said guideway forming means thatare in engagement with said support members when said carrier is in saidsecond position being downwardly inclined in a second directionperpendicular to said first direction; and selectively operable powermeans for producing relative movement in said second direction betweensaid support members and said downwardly inclined portions of saidsupport surface to thereby permit said support members to move down saidinclined portion of said support surface to bring said frame intoengagement with said bed.

2. In a press having a bed, a frame, a ram carried by said frame andmovable vertically toward and away from said bed, tracks extending in afirst direction from a position exterior of said press into and acrosssaid bed, a carrier having wheels engageable with said tracks forguiding said carrier therealong from a first position exterior of saidpress to a second position within said press and beneath said ram, theimprovement comprising: means operable when said carrier is in saidsecond position for lowering said carrier against said bed and relievingthe weight of said carrier from said Wheels; said means including firsttrack forming members having upwardly facing surfaces downward-1yinclined in a direction perpendicular to said first direction, saidtrack forming members being positioned in said bed at locationscorresponding to the location of said wheels when said carrier is insaid second position for supporting said wheels on said upwardly facingsurfaces; and selectively operable power means for moving said trackforming members horizontally in said second direction away from saidwheels to permit said wheels and said carrier to be lowered.

3. The improvement as defined in claim 2 wherein said wheels have anouter periphery which is inclined in a direction corresponding to theincline of said upwardly facing surfaces of said track forming members.

4. The improvement as defined in claim 2 wherein at least some of saidtrack forming members include transversely extending clamp membersadapted to engage said carrier as said track forming members are movedaway from said wheels.

5. The improvement as defined in claim 2 wherein at least some of saidtrack forming members include locating means adapted to engage saidcarrier as said track forming members are moved away from said wheels.

6. The improvement as defined in claim 2 wherein said wheels have aV-shaped outer periphery, and a pair of 7 8 said track forming sectionsare positioned at each looa- 3,229,791 1/1966 Soman 100-299 tioncorresponding to the locations of said wheels when 3,368,479 2/1968Gregorovich 100-229 said carrier is in said second position.

CHARLES W. LANHAM, Primary Examiner.

References Cited 5 G. P. CROSBY, Assistant Examiner. UNITED STATESPATENTS 2,988,234 6/1961 Barothy 100 299 P224, 229, 299

2,996,025 8/1961 Georgefi'f 100 299

